1. Field of the Invention
This invention is generally directed to access devices for introducing and delivering a catheter cannula or sheath into an artery, vein, vessel, body cavity, or drainage site.
2. Description of the Related Art
A preferred non-surgical method for inserting a catheter or vascular sheath into a blood vessel involves the use of the Seldinger technique, which includes an access needle that is inserted into a patient's blood vessel. A guidewire is inserted through the needle and into the vessel. The needle is removed, and a dilator and sheath combination are then inserted over the guidewire. The dilator and sheath combination is then inserted a short distance through the tissue into the vessel, after which the dilator and guidewire are removed and discarded. The catheter may then be inserted through the sheath into the vessel to a desired location.
A number of vascular access devices are known. U.S. Pat. Nos. 4,241,019, 4,289,450, 4,756,230, 4,978,334, 5,124,544, 5,424,410, 5,312,355, 5,212,052, 5,558,132, 5,885,217, 6,120,460, 6,179,823, and 6,210,332 disclose examples of such devices. None of these devices, however, has the ease and safety of use that physicians and other healthcare providers would prefer and, thus, there is a need for an easier-to-use and safer vascular access device, especially one that would clearly indicate when a blood vessel has been punctured.